QLocale: Update Portuguese and Greek locales data

* Update timeFormat for Portuguese/Brazil locale.
* Update abbreviated day names for Greek locale.

Note: Those locales are already fixed in the recent CLDR v23.1
data used in Qt 5.2.

Change-Id: I351e3a9ae65dcff4ab6b4787242141c3c9d86e24
Reviewed-by: Lars Knoll <lars.knoll@digia.com>